In customary household washing methods, the problem exists that some types of soil and dirt are difficult to remove from textiles when using suboptimal detergent formulations and/or low wash temperatures, because these soils and dirt are strongly attached to the fiber surface or are strongly absorbed inside the fibers.
The use of several agents as soil release agents in laundry processes is known. Examples are carboxymethyl cellulose or anionic derivatives of polymers from terephthalic acid and polyethylene glycol (see e.g. E. Smulders in “Laundry Detergents” Wiley-VCH Verlag GmbH, 2002, page 88). Regarding soil release agents it is often assumed that these are deposited and accumulated on the fiber surface during laundry washing, thereby modifying the surface properties of the fibers. Soil and dirt that is subsequently deposited onto this modified fiber surface is easier released in a subsequent washing cycle. In PCT/EP2012/071020 (not published yet) the use of one or more comb or block copolymers as soil antiredeposition agents and soil release agents in aqueous laundry processes has been described.
There is a need to provide block copolymers for use as soil release agents in laundry processes. Additionally, there is a need to provide liquid and powder detergent compositions suitable for that use.